RIDGID 37835 Manual Threader Pipe Dies, Right-Handed Alloy NPT Pipe Dies with Nominal Pipe Size of 1-Inch for Ratchet Threaders or 3-Way Pipe Threaders Manual threading dies for OO-R, 111-R, 12-R, O-R, 11-R Ratchet threaders Pipe dies also work with 30A, 31A 3-Way Pipe Threaders Manual threading pipe dies with nominal pipe size of 1-inch Alloy threading die material RIDGID 37835 NPT dies have 11-1/2 TPI (Threads Per Inch)